That’s right, Sherlock series four will finally hit our screens on New Year’s Day 2017, with things set to get incredibly tense.

Between shots of a stubbled Sherlock and a pensive Watson, we see plenty of drama unfold, with the trailer telling us: “Everything they know will be tested...Everyone they know is under threat.”

Benedict Cumberbatch has even warned that following the happenings in the upcoming series, which is set to delve deeper into Sherlock's past, fans of the show will likely need a break following the finale, due to the incredibly intense plotline.

In a recent interview, the actor explained why cast and crew are likely to leave a longer gap than normal between series four and the filming of a future series five, telling reporters: “I think there will be a lull. I don't think it will be in a year and a half necessarily but we will wait and see and maybe it will be.

“First and foremost we have got a fourth series for people to watch and understand and when they watch it they might go 'Oh yeah, maybe there does need to be a break now' because of what happens in it. No spoilers!”